Ringshaft-furnace



July 8, 1958 BERZ RINGSHAFT-FURNACE Filed Oct. 12, 1954 FIG.I

INVENTOR. Max Berz BY 7dymwdf 11,7 7

ATTORNEY RINGSHAFT-FURNACE Max Berz, Kochel am See, Germany Application October 12, 1954, Serial No. 461,870

a 6 Claims. Cl. 263-49) The present invention relates to a ringshaft furnace in which heating gases, e. g. waste gases are passed through material to be heated.

More particularly the invention relates to a ringshaftfurnace which is supposed to work as a pre-heater, for instance in connection with a rotary calciner or kiln. In a ringshaft-furnace according to the present invention granulated material, e. g. cement, magnesite, dolomite, may be pre-heated by means of waste gases before entering the kiln for final treatment.

The object of the present invention is to provide a heating device of the type mentioned, in which a thorough heating can be accomplished by simple and inexpensive means.

This is achieved, according to the invention, by admitting the heating gases to the material from an inner feed channel, whereby large admission openings or areas are provided for the gases, whereas the discharge openings for the heated material are so designed as to have smaller dimensions. In this way, low velocity of the heating gas is secured, with uniform gas distribution and low pressure of air within the material to be heated.

Another advantage of the arrangement is the uniform undisturbed flow of the material to the discharge openings due to the convenient angle of the slope from which the material is delivered to said openings.

The design for the ringshaft furnace according to the invention is space-saving. The admission channel of the gases is closed by a vault that deflects the oncoming gases which are passed into the material through openings lying above the discharge opening for the material. These present a large surface as they spread out sloping down from the admission duct.

A cone-shaped ring surface forming the support for the inclined material to be met by the oncoming heating gases is provided by two ring structures made of refractory bricks of appropriate shape, which also provide the discharge openings for the heated material. The two rings, circular discs, or the like, are spaced at an appropriate distance from one another and have different outer diameters, whereby the angle of the sloping material is formed. A

In one embodiment of the invention, the upper ring is made as a suspension structure. In another embodiment, the upper and lower rings are joined by pillars in such a way, that evenly distributed openings are formed at the inner periphery. In this case the pillars serve also as supports for the circular rings or discs and for the vault. Instead of using circular rings, polygonal elements may be employed.

In order to provide for admission of gas to the material without disturbances and losses, the two rings are shaped to form a suitable nozzle. In some cases it is possible to provide a plurality of upper rings with different decreasing diameters, in which case several admission planes are formed above the discharge openings.

In the accompanying drawing, two embodiments of the ringshaft furnace according to the invention are illustrated by way of; example,

that many changes in the details can bemade without but it should be understood departing from the spiritiof' the invention.

- Fig. 1 shows a vertical section'through'an embodiment of a. ringshaft furnace with suspension'structure of theupper ring and Fig. 2 illustrates 'in a vertical section a similar structure comprising pillars between the upper and lower rings.

Fig. 3 shows schematicallya diagrammatic vie'w partly in section of the ringshaft-furnace Referring now to Fig. 1, the ringshaft is designated by a; it is filled by conventional means (not shown in the drawing) with material to be heated, which slope toward the interior between an upper ring a and a lower ring a. The upper ring 0 is a suspension-construction. The lower ring d is supportedby the bottom of the shaft structure and discharge openings e are provided for the treated material. A reciprocating pusher f, or a similar element serves for discharging the heater material. The rings 0 and d have different outer diameters and may be shaped in nozzle form to insure proper waste gas passage.

Waste gases are admitted by a central channel b and pass through the material in the direction of the arrows. A vault k which is supported by ring 0 closes ofi the gas admission at the top and acts as a baflle for deflecting vfree between them discharge openings i and admission openings h. The vault k forms again the closure of the admission channel b for the waste gases and is in this case supported by the pillars g. As mentioned before, instead of ring shapes 0, d, l, m, I may use polygonal structures.

Instead of using only two rings or polygons, several elements may be used with decreasing outer diameter.

Referring to Fig. 3 a kiln designated by n is provided with a channel 0 through which gases emerging from said kiln ascend into the ringshaft-furnace p thereby pre-heating granulated material contained in said ringshaft furnace. By means of pushers q the pre-heated material is discharged through openings not shown in the drawing into the channel 0 in counter-current through t the heating gases ascending through the same and moving at low velocity into the ringshaft-furnace n.

The exhausted heating gases are removed through channel r from the ringshaft-furnace by suction. A smooth continuous motion of the heating gases in one direction and the outgoing granules in the other direction in the ringshaft-furnace according to the invention, is reached by the provision of a convenient angle of the slope from which the material to be treated is delivered to the discharge openings.

What I claim is:

l. A ringshaft furnace for heating material by means of waste gases, comprising in combination a shaft forming a ring chamber for the material to be heated, a central interior admission channel for the waste gases to said chamber, a vault at the top of said admission channel serving as a baffle for deflecting said waste gases through the material to be heated, openings for the discharge of said material through said admission chan- Pat'ente'd July 8, 1958 connected to the'kil'n.

annular member and the bottom of the heating chamber.

2. A ringshaft furnace according to claim 1, wherein the annular members are ring-shaped.

3. A ringshaft furnace according to claim 1, wherein pillars are provided for joining the upper and the lower annular members. I t

4. A ringshaft furnace according to claim 1, wherein pillars are provided for joining the upper and the lower annular members, said pillars forming therebetween evenly distributed openings at their inner circumference for even distribution of the gas admission, and serve as a support for the vault.

5. A ringshaft furnace according to claim 1, wherein the upper andlower annular members are shaped as a nozzle for: the entering gases.

A 0 6:1 ringshaft furnace according to claim 1, having aplurality-of upper annular members of decreasing di- References Citedin' the file of this patent UNITED STATES PATENTS 462,876 Kerr Nov. 10, 1891 475,398 Heckert et a1; May 24, 1892 2,002,010 Hilliard May 21, 1935 15 2,593,345 Robinson Apr. 15, 1952 

